Shopping carts are known in the art and generally include a frame, a main container, wheel assemblies and a handle for pushing the cart. Traditionally, such carts were made primarily of metal for durability and ease of fabrication. However, several factors, including increases in production costs due to rising material and labor costs, as well as maintenance costs related to repairing seat mechanisms and wheel assemblies have made such traditional designs less desirable.
Known shopping carts are commonly designed to be nestable into another, similarly constructed cart and to enable a following, similarly constructed cart to be nested into the shopping cart. Commonly, in retail stores and in parking areas near retail stores, long lines of nested shopping carts may be formed which must be moved by store personnel.
Typically, the rear casters of a shopping cart, unlike the front casters, does not swivel. Such arrangement is generally desirable as it allows for ease of control and maneuvering of a single shopping cart with little effort. However, such arrangement commonly results in high stresses applied to the rear casters and wheels when a line of nested shopping carts is moved. Such stresses tend to cause portions of the rear castors to bend and break and tends to cause the bearings and treads of said castors to wear excessively, particularly as attempts are made to turn a line of nested shopping carts.
U.S. Pat. Nos. 6,923,456 B2 and 7,216,875, the disclosures of which are incorporated by reference herein, describe shopping carts being nestable similarly and having a rear caster-lifting capabilities. However such designs are directed toward use on traditional metal carts which leave much room for improvement.
Accordingly, a need exists in the art for shopping carts that are less expensive to manufacture and to maintain.